Start year
1995
Organizational Unit
Organizing institutions
General
Description
Our goal is to study the processes that lead to the formation of low mass stars, brown dwarfs and planets and to characterize the physical properties of these objects in various evolutionary stages. Low mass stars and brown dwarfs are likely the most numerous type of objects in our Galaxy but due to their low intrinsic luminosity they are not so well known. We aim to study the frequency, multiplicity and spatial distribution of these objects in the solar neighbourhood and in nearby star forming regions and stellar clusters in order to better understand the mechanism of formation, characterise their optical and infrared properties and establish the relation between spectral properties, mass and luminosity.. Most of our effort will be dedicated to push toward lower mass limits the detection of these astros either bounded to stars and brown dwarfs and/or free-floating in interstellar space. The lowest mass objects display a lower intrinsic luminosity and cooler effective temperatures thus they are remarkably difficult to detect using direct imaging techniques. However, these techniques allow a full photometric and spectroscopic characterization and a best determination of their physical and chemical properties. We also aim to investigate the presence of planets around low mass stars using radial velocity measurements and techniques for high spatial resolution imaging. We will develop ultrastable spectrographs for large telescopes and systems for ultrafast imaging. With the spectrographs it would be possible to detect planets of similar mass to the Earth around G, K and M-type stars. The goal is to establish the frequency of these planets in stars of the solar neighbourhood and characterise the properties of the associated planetary systems.
Members
Principal investigator
Prof.
Rafael
Rebolo López
Project staff
Víctor Javier
Sánchez Bejar
Nicolas Cédric
Lodieu
Jonay Isai
González Hernández
Patricia
Chinchilla Gallego
Collaborators
Dr.
M.R. Zapatero Osorio
Dr.
A. Pérez-Garrido
Dr.
I. Villo
Dr.
A. Díaz Sánchez
Dr.
E. Jodar
Dr.
C. McKay
Dr.
D. King
Dr.
T. Henning
Dr.
R. Mundt
Dr.
G. Bihain
Dr.
P. Lucas
Dr.
D. Pinfield
Dr.
H. Jones
Dr.
F. Marocco
Dr.
M.T. Ruiz
Dr.
L. Labadie
Dr.
Ya. Pavlenko
Dr.
R. Smart
Dr.
A. Burgasser
Dr.
F. Allard
Dr.
R. Raddi
Results
- The optical and near-infrared sequence of 10 Myr-old L dwarfs in the nearest OB association to the Sun, Upper Scorpius
- The lithium depletion boundary of the Hyades cluster.
Scientific activity
Related publications
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Characterisation of TOI-406 as a showcase of the THIRSTEE program: A two-planet system straddling the M-dwarf density gapContext. The exoplanet sub-Neptune population currently poses a conundrum, as to whether small-size planets are volatile-rich cores without an atmosphere, or rocky cores surrounded by a H-He envelope. To test the different hypotheses from an observational point of view, a large sample of small-size planets with precise mass and radius measurementsLacedelli, G. et al.
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122024 -
The obliquity and atmosphere of the hot Jupiter WASP-122b (KELT-14b) with ESPRESSO: An aligned orbit and no sign of atomic or molecular absorptionThanks to their short orbital periods and hot extended atmospheres, hot Jupiters are ideal candidates for atmosphere studies with high- resolution spectroscopy. New stable spectrographs help improve our understanding of the evolution and composition of those types of planets. By analyzing two nights of observations using the ESPRESSO highStangret, M. et al.
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112024 -
A sub-Earth-mass planet orbiting Barnard's starContext. ESPRESSO guaranteed time observations (GTOs) at the 8.2m VLT telescope were performed to look for Earth-like exoplanets in the habitable zone of nearby stars. Barnard's star is a primary target within the ESPRESSO GTO as it is the second closest neighbour to our Sun after the α Centauri stellar system. Aims. We present here a large set ofGonzález Hernández, J. I. et al.
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102024 -
The atmospheric composition of the ultra-hot Jupiter WASP-178 b observed with ESPRESSOContext. Ultra-hot Jupiters (UHJ) have emerged as ideal testbeds for new techniques for studying exoplanet atmospheres. Only a limited number of them are currently well studied, however. Aims. We search for atmospheric constituents for the UHJ WASP-178 b with two ESPRESSO transits. Additionally, we show parallel photometry that we used to obtainDamasceno, Y. C. et al.
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92024 -
ESPRESSO reveals blueshifted neutral iron emission lines on the dayside of WASP-76 bContext. Ultra hot Jupiters (gas giants with T eq > 2000 K) are intriguing exoplanets due to the extreme physics and chemistry present in their atmospheres. Their torrid daysides can be characterised using ground-based high-resolution emission spectroscopy. Aims. We search for signatures of neutral and singly ionised iron (Fe I and Fe IICosta Silva, A. R. et al.
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92024 -
Three super-Earths and a possible water world from TESS and ESPRESSOContext. Since 2018, the ESPRESSO spectrograph at the VLT has been hunting for planets in the southern skies via the radial velocity (RV) method. One of its goals is to follow up on candidate planets from transit surveys such as the TESS mission, with a particular focus on small planets for which ESPRESSO's RV precision is vital. Aims: We aim toHobson, M. J. et al.
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82024 -
TESS and ESPRESSO discover a super-Earth and a mini-Neptune orbiting the K-dwarf TOI-238*The number of super-Earth and mini-Neptune planet discoveries has increased significantly in the last two decades thanks to transit and radial velocity (RV) surveys. When it is possible to apply both techniques, we can characterise the internal composition of exoplanets, which in turn provides unique insights on their architecture, formation andD'Odorico, V. et al.
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52024 -
The compact multi-planet system GJ 9827 revisited with ESPRESSO★GJ 9827 is a bright, nearby K7V star orbited by two super-Earths and one mini-Neptune on close-in orbits. The system was first discovered using K2 data and then further characterized by other spectroscopic and photometric instruments. Previous literature studies provide several mass measurements for the three planets, however, with large variationsPassegger, V. M. et al.
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42024 -
An ESPRESSO view of the HD 189733 system. Broadband transmission spectrum, differential rotation, and system architectureContext. The development of state-of-the-art spectrographs has ushered in a new era in the detection and characterization of exoplanetary systems. The astrophysical community now has the ability to gain detailed insights into the composition of atmospheres of planets outside our Solar System. In light of these advancements, several new methods haveCristo, E. et al.
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22024 -
New Mass and Radius Constraints on the LHS 1140 Planets: LHS 1140 b Is either a Temperate Mini-Neptune or a Water WorldThe two-planet transiting system LHS 1140 has been extensively observed since its discovery in 2017, notably with Spitzer, HST, TESS, and ESPRESSO, placing strong constraints on the parameters of the M4.5 host star and its small temperate exoplanets, LHS 1140 b and c. Here, we reanalyze the ESPRESSO observations of LHS 1140 with the novel line-byCadieux, Charles et al.
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12024 -
The CARMENES search for exoplanets around M dwarfs. Telluric absorption corrected high S/N optical and near-infrared template spectra of 382 M dwarf starsLight from celestial objects interacts with the molecules of the Earth's atmosphere, resulting in the production of telluric absorption lines in ground-based spectral data. Correcting for these lines, which strongly affect red and infrared wavelengths, is often needed in a wide variety of scientific applications. Here, we present the templateNagel, E. et al.
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122023 -
TOI-1801 b: A temperate mini-Neptune around a young M0.5 dwarfWe report the discovery, mass, and radius determination of TOI-1801 b, a temperate mini-Neptune around a young M dwarf. TOI-1801 b was observed in TESS sectors 22 and 49, and the alert that this was a TESS planet candidate with a period of 21.3 days went out in April 2020. However, ground-based follow-up observations, including seeing-limitedGoffo, E. et al.
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122023 -
Planetary companions orbiting the M dwarfs GJ 724 and GJ 3988. A CARMENES and IRD collaborationWe report the discovery of two exoplanets around the M dwarfs GJ 724 and GJ 3988 using the radial velocity (RV) method. We obtained a total of 153 3.5 m Calar Alto/CARMENES spectra for both targets and measured their RVs and activity indicators. We also added archival ESO/HARPS data for GJ 724 and infrared RV measurements from Subaru/IRD for GJGorrini, P. et al.
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122023 -
Photometric follow-up of the 20 Myr old multi-planet host star V1298 Tau with CHEOPS and ground-based telescopesContext. The 20 Myr old star V1298 Tau hosts at least four planets. Since its discovery, this system has been a target of intensive photometric and spectroscopic monitoring. To date, the characterisation of its architecture and planets' fundamental properties has been very challenging. Aims: The determination of the orbital ephemeris of theDamasso, M. et al.
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122023 -
The GAPS programme at TNG. XLVIII. The unusual formation history of V1298 TauContext. Observational data from space- and ground-based campaigns have revealed that the 10-30 Ma old V1298Tau star hosts a compact and massive system of four planets. Mass estimates are available for the two outer giant planets and point to unexpectedly high densities for their young ages. Aims: We investigate the formation of these two outermostTurrini, D. et al.
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112023 -
A compact multi-planet system transiting HIP 29442 (TOI-469) discovered by TESS and ESPRESSO. Radial velocities lead to the detection of transits with low signal-to-noise ratioContext. One of the goals of the Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) Guaranteed Time Observations (GTO) consortium is the precise characterisation of a selected sample of planetary systems discovered by TESS. One such target is the K0V star HIP 29442 (TOI-469), already known to host a validatedDamasso, M. et al.
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112023 -
Optical properties of metal-poor T dwarf candidatesContext. Metal-poor brown dwarfs are poorly understood because they are extremely faint and rare. Only a few candidates have been identified as T-type subdwarfs in infrared surveys and their optical properties remain unconstrained. Aims: We aim to improve the knowledge of the optical properties of T subdwarf candidates to break the degeneracyZhang, J. -Y. et al.
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102023 -
Young nearby open clusters and their luminosity functionsContext. Open clusters are groups of coeval stars sharing properties such as distance and metallicity, and they are key to understanding stellar evolution. Aims: Our main goal is to study the evolution of open clusters with a special focus on the universality of the luminosity function. Methods: We applied an upgraded version of the convergentŽerjal, M. et al.
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102023 -
GJ 806 (TOI-4481): A bright nearby multi-planetary system with a transiting hot low-density super-EarthOne of the main scientific goals of the TESS mission is the discovery of transiting small planets around the closest and brightest stars in the sky. Here, using data from the CARMENES, MAROON-X, and HIRES spectrographs together with TESS, we report the discovery and mass determination of aplanetary system around the M1.5 V star GJ 806 (TOI-4481)Palle, E. et al.
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102023 -
The CARMENES search for exoplanets around M dwarfs. Behaviour of the Paschen lines during flares and quiescenceThe hydrogen Paschen lines are known activity indicators, but studies of them in M dwarfs during quiescence are as rare as their reports in flare studies. This situation is mostly caused by a lack of observations, owing to their location in the near-infrared regime, which is covered by few high-resolution spectrographs. We study the Paβ line, usingFuhrmeister, B. et al.
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102023
